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HAND-BOOK OF ACOUSTICS. |
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The vibration numbers of the upper or lower octaves of these notes, are of course at once obtained by doubling or halving them.
It will be noticed that a scale may be constructed on any vibration number as a foundation. The only reason for selecting 288 was, to avoid fractions of a vibration and so simplify the calculations. As another example let us take d = 200. Proceeding in the same way as before, but tabulating at once, for the sake of brevity, we get |
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We may now adopt the reverse process, that is, from the vibration numbers, obtain the vibration ratios. For example, using the first scale, we find that the vibration number of t is to that of n as 540 : 360, that is (dividing each by 180, for the purpose of simplifying) as 3 : 2 ; or more concisely
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